Bone conduction skin interface

Abstract

A skin interface apparatus configured as an interface of a prosthesis with skin of a recipient, including a first portion configured for direct contact with skin of the recipient, and a second portion configured for direct contact with skin of the recipient, wherein the portions have different material properties. In an exemplary embodiment, the first portion is a part of a holding plate pad of a hearing prosthesis and the second portion is part of a driving plate pad of the hearing prosthesis.

What is claimed is: 
     
       1. A skin interface apparatus configured as an interface of a prosthesis with skin of a recipient, comprising:
 at least one permanent magnet configured to magnetically retain the skin interface apparatus to the skin via interaction with an implanted magnet implanted beneath the skin of the recipient; 
 a first portion configured for direct contact with skin of the recipient; and 
 a second portion configured for direct contact with skin of the recipient, wherein 
 the portions have different material properties, 
 the skin interface apparatus is configured to support the magnet such that the magnet is spaced away from the skin of the recipient, 
 the first portion is configured to transfer vibrations therethrough at a first transmissibility value, and 
 the second portion is configured to transfer vibrations therethrough at a second transmissibility value substantially higher than the first transmissibility value. 
 
     
     
       2. The skin interface apparatus of  claim 1 , wherein:
 the first portion is a part of a holding plate pad of a hearing prosthesis and the second portion is part of a driving plate pad of the hearing prosthesis. 
 
     
     
       3. The skin interface apparatus of  claim 1 , wherein:
 the first portion has a material property that renders the first portion softer than the second portion. 
 
     
     
       4. The skin interface apparatus of  claim 1 , wherein:
 the second portion has a material property that is more conductive to vibrations than the first portion. 
 
     
     
       5. The skin interface apparatus of  claim 1 , wherein:
 the first portion has a surface area that interfaces with the skin of the recipient that is at least three times that of the second portion. 
 
     
     
       6. A removable component of a passive transcutaneous bone conduction device, comprising:
 an actuator; and 
 the skin interface apparatus of  claim 1 . 
 
     
     
       7. The skin interface apparatus of  claim 1 , wherein:
 the first portion is elastically different than the second portion. 
 
     
     
       8. A skin interface assembly for an external component of a bone conduction device, comprising:
 a support assembly; and 
 a drive assembly, wherein 
 the support assembly is configured to react against at least substantially all of a retention force between the external component and skin of a recipient of the bone conduction device, 
 the driving assembly is configured to vibrate in response to sound captured by the external component of the bone conduction device, and 
 the support assembly includes a first removable skin interface pad and the driving assembly includes a second removable skin interface pad. 
 
     
     
       9. The skin interface assembly of  claim 8 , wherein:
 the first removable skin interface pad is separated by an open space from the second removable skin interface pad that completely surrounds the second removable skin interface pad. 
 
     
     
       10. The skin interface assembly of  claim 8 , wherein:
 the first removable skin interface pad is directly connected to the second removable skin interface pad such that the pads contact each other. 
 
     
     
       11. The skin interface assembly of  claim 8 , wherein:
 the first removable skin interface pad is indirectly connected to the second removable skin interface pad. 
 
     
     
       12. The skin interface assembly of  claim 8 , wherein:
 the first removable skin interface pad is loosely coupled to the second removable skin interface pad such that removal of the first skin interface pad from the external component also removes the second skin interface pad and such that the first removable skin interface pad is substantially vibrationally isolated from the second removable skin interface pad. 
 
     
     
       13. The skin interface assembly of  claim 8 , wherein:
 the first removable skin interface pad is in direct contact with the second removable skin interface pad, wherein the first removable skin interface pad has different material properties than the second removable skin interface pad. 
 
     
     
       14. The skin interface assembly of  claim 8 , wherein:
 the first removable skin interface pad is completely separated from the second removable skin interface pad; and 
 the second removable skin interface pad is coupled to the first removable skin interface pad only by a path that extends from the second pad to the first removable skin interface pad while passing thorough the driver apparatus. 
 
     
     
       15. The skin interface assembly of  claim 8 , further comprising:
 a third removable skin interface pad configured to at least one of dampen, reflect or diffuse transduction of vibrations from the skin of vibrations generated by the drive apparatus transmitted through skin of the recipient. 
 
     
     
       16. A skin interface pad assembly for an external component of a passive bone conduction device, comprising:
 a first pad portion configured to interface with skin of the recipient; and 
 a second pad portion configured to interface with skin of the recipient, wherein 
 the first pad portion is made of different material than the second pad portion, and 
 the first pad is configured to transfer vibrations therethrough at a first transmissibility value, and 
 the second pad is configured to transfer vibrations therethrough at a second transmissibility value substantially higher than the first transmissibility value. 
 
     
     
       17. The skin interface pad assembly of  claim 16 , wherein:
 the first pad portion is made of a visco-elastic polymer and the second pad portion is made of a material that is less elastic than the first pad portion. 
 
     
     
       18. The skin interface pad assembly of  claim 16 , wherein:
 the first pad portion is made of a soft sponge material. 
 
     
     
       19. The skin interface pad assembly of  claim 16 , wherein:
 the first pad portion is made of a pseudoplastic material. 
 
     
     
       20. The skin interface pad assembly of  claim 16 , wherein:
 the first pad portion is made of a foam. 
 
     
     
       21. The skin interface pad assembly of  claim 16 , wherein:
 the second pad portion is made of a memory foam having a vibrational transmissivity greater than the first pad portion. 
 
     
     
       22. The skin interface pad assembly of  claim 16 , wherein:
 the second pad portion is made of a dilatant material. 
 
     
     
       23. A removable component of a bone conduction device, comprising:
 a first skin interface apparatus configured to serve as an interface between a support apparatus of the device and skin of a recipient; and 
 a second skin interface apparatus configured to serve as an interface between a vibratory apparatus of the device and skin of the recipient, wherein 
 the skin interface apparatuses are different, and 
 the first skin interface apparatus includes a first component configured to directly contact the skin of the recipient and a second component located relative to a side of the first component that is away from the skin of the recipient. 
 
     
     
       24. The component of  claim 23 , wherein:
 the first skin interface apparatus is an elastic pad. 
 
     
     
       25. The component of  claim 23 , wherein:
 the first skin interface apparatus is configured to dampen vibrations more than the second skin interface apparatus. 
 
     
     
       26. The component of  claim 23 , wherein:
 the first component is configured to absorb vibrations; and 
 the second component is configured to reflect vibrations. 
 
     
     
       27. The component of  claim 23 , wherein:
 at least one of a first face of the first component or a second face of the second component facing one another has a surface geometry that is non-planar. 
 
     
     
       28. The component of  claim 23 , wherein:
 at least one of a first face of the first component or a second face of the second component facing one another has a surface geometry configured to create diffuse vibrational reflections. 
 
     
     
       29. The component of  claim 23 , further comprising:
 a vibration management component, wherein 
 the vibration management component is separate from the first skin interface apparatus and the second skin interface apparatus, and 
 the vibration management component is configured to at least one of dampen or reflect or diffuse vibrations transducted from the skin of the recipient. 
 
     
     
       30. The skin interface assembly of  claim 8 , wherein:
 the skin interface assembly is configured to be removed from skin of the recipient. 
 
     
     
       31. The skin interface assembly of  claim 8 , wherein:
 the first removable skin interface pad contacts the second removable skin interface pad at lateral boundaries thereof. 
 
     
     
       32. The skin interface pad assembly of  claim 16 , wherein:
 the pads are not in contact with magnetic material. 
 
     
     
       33. The skin interface pad assembly of  claim 16 , wherein:
 the skin interface pad assembly is devoid of any plate component that contacts the pads.